In the recent electronics industry, wearable devices are emerging as a successor to smart phones.
Wearable devices are collectively referred to as electronic devices that can be worn on the body while performing smart functions, and that input, output, and process information.
Currently, the world wearable device market is at an early stage, but research and development associated with the wearable devices is accelerating, and global companies are also anticipating that new products will be released in the future, and that the market will be open in the future and grow rapidly.
The wearable device may be implemented in the form of being worn on the body without carrying it in the hand, and may be applied to products which can become part of the body. Basically, the wearable device may be applied to various kinds of products of shirts, pants, accessories such as glasses, bracelets, and watches, and shoes.
Typically, smart watches and smart glasses may be referred to as smart devices. Here, smart watches may function as watches worn on the wrist, perform phone functions like a mobile phone, and implement various smart functions such as text messaging, e-mail, and web surfing. Smart glasses may include glasses functions, camera functions and image viewing functions.
Meanwhile, since the wearable device is an electronic device, a wearable printed circuit board is required and its performance makes an influence upon product characteristics.
Korean Patent Application Publication No. 10-2015-0089283 discloses a wearable terminal including: a communication unit for communicating with at least one external device; a memory unit for storing at least one of an image to be photographed and a sound to be sensed; a biometric information detection unit for detecting biometric information from a user's body; and a control unit for controlling the communication unit to transmit at least one of the stored image and sound to the external device according to the detected biometric information. However, the wearable terminal of Korean Patent Application Publication No. 10-2015-0089283 does not disclose a detailed description of a printed circuit board on which the communication unit, the biometric information detection unit, and the control unit are electrically connected.
Korean Patent Registration No. 10-1139970 discloses a method of manufacturing a flexible printed circuit board including: a first step of forming a circuit pattern on a seed layer formed on a soft insulating substrate; a second step of applying a first photosensitive material on the circuit pattern; a third step of exposing and developing the first photosensitive material to form a protective pattern on the circuit pattern; a fourth step of etching the seed layer; and a fifth step of removing the protective pattern, wherein the first photosensitive material is a liquid or film type photosensitive material, to thereby implement the flexible printed circuit board. Since a base member is a soft insulating substrate such as a polyimide film, there is no restoring characteristic of being unfolded or re-spread after being folded or wrinkled, and there is no air-permeability to thus cause inconveniences when worn. As a result, the characteristics of the wearable device may be deteriorated.